This is Wednesday’s storm coverage. Read the latest with Friday’s live updates on Hurricane Irma.

• Hurricane Irma, one of the strongest storms ever recorded in the Atlantic, hit the eastern Caribbean on Wednesday with winds of up to 185 miles an hour, but had slowed to 180 m.p.h. by Thursday morning.

• The Category 5 storm leveled Barbuda, damaging 95 percent of its buildings and leaving the island “barely habitable.” It has since begun lashing Puerto Rico and is also threatening havoc and destruction in the Virgin Islands, the Dominican Republic, Haiti and Cuba. The Bahamas and the Turks and Caicos Islands will also be at risk on Thursday.

• The French interior minister, Gerard Collomb, said at least eight people had been killed in French Caribbean territory, and at least three deaths were reported elsewhere. The authorities warned that the toll would rise as communications improved.

• President Trump declared a state of emergency in Florida, Puerto Rico and the United States Virgin Islands. The storm is expected to reach Florida early on Saturday, potentially causing catastrophic flooding.

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‘Barbuda is literally rubble,’ but Antigua is spared.

Early on Wednesday, Prime Minister Gaston Browne of Antigua and Barbuda said his nation had been spared the worst of the hurricane, declaring in a statement, “The essential point is that our main infrastructure has stood up and our country can resume normal life within hours.” He went so far as to add, “I dare to say that no other country in the Caribbean would have been as well prepared as we were.”

This turned out to be stunningly inaccurate: While the damage in Antigua was not as severe as expected, Mr. Browne announced in the afternoon that 95 percent of all structures on its sister island, Barbuda, had been damaged or destroyed, rendering the island “barely habitable.” A telecommunications tower was broken in two. At least one person, an infant, was killed.

Barbuda, home to about 1,600 people (3 percent of the country’s population), “is literally rubble,” the prime minister told ABS TV/Radio Antigua.

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The prime minister of Antigua and Barbuda, Gaston Browne, described how the island of Barbuda was nearly leveled by Hurricane Irma.

In his initial statement Wednesday morning, Mr. Browne suggested he had been receiving reports from Barbuda. But he later clarified that, in fact, the storm had knocked out all official communication systems on the island, rendering officials there unreachable after the storm. As a result, it was not until the afternoon, when the prime minister surveyed Barbuda from the air, that the extent of the devastation became clear.

“What I saw was heart-wrenching — I mean, absolutely devastating,” Mr. Browne told ABS TV afterward, estimating that it would take at least $150 million to return the island to some semblance of normalcy.

“Hurricane Irma would have been easily the most powerful hurricane to have stormed through the Caribbean,” he said, “and it is extremely unfortunate that Barbuda was right in its path.”

Mr. Browne said he had been caught off guard by the utter destruction in Barbuda because it is so close to the comparatively unscathed Antigua. The islands are less than 40 miles apart.

— CARL JOSEPH, KIRK SEMPLE and MAGGIE ASTOR

‘Considerable’ damage in the French Caribbean.

President Emmanuel Macron of France said on Wednesday evening that it was too early to say how badly the islands of St. Martin and St. Barthélemy had been damaged or how many casualties there were. But French officials reported that the death toll was at least two, and Mr. Macron said the aftermath would be “harsh and cruel.”

“We will have victims to lament, and the material damage on the two islands is considerable,” he said after a crisis meeting in Paris, adding that the “entire nation” stood beside the inhabitants of the islands.

Mr. Macron said that emergency services were focusing on re-establishing contact with the affected areas and that rescue operations would be coordinated from the French Caribbean island of Guadeloupe, where the French minister for overseas territories, Annick Girardin, was headed on Wednesday evening.

In the Virgin Islands, ‘it feels seismic.’

Javorn Micheal Fahie, a taxi driver in Tortola, in the British Virgin Islands, said most of the galvanized steel roofs in his neighborhood had blown off. He saw two of them, from houses facing his, flying away in the wind.

“Oh boy,” he said in an internet phone call from his concrete house in the Johnson’s Ghut area of the island, where he had been riding out the storm all day and posting videos of it on his Facebook page. “A lot of wind and rain.”

“All the trees around us have no leaves,” he added. “Everything is empty.”

Late on Wednesday, the Federal Emergency Management Agency tweeted a photo from a resident of St. Thomas, in the United States Virgin Islands.

Earlier in the day, Kelsey Nowakowski, who lives in St. Thomas, described how she and four friends had hunkered down and waited for the storm to pass.

“We’ve all been in hurricanes before, but have never felt anything like this before,” Ms. Nowakowski said in a message via Twitter. “It feels seismic, it feels catastrophic.”

— RICHARD PÉREZ-PEÑA and KIRK SEMPLE

In Puerto Rico, fears of rising waters.

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The sea rose in Fajardo, P.R., on Tuesday. The island’s governor warned that flooding was a concern.CreditRicardo Arduengo/Agence France-Presse — Getty Images

Gov. Ricardo A. Rosselló said at a televised briefing on Wednesday that six to eight inches of rain were expected in Puerto Rico, with some areas receiving up to 12 inches.

“As the history with Harvey states,” he said, referring to the hurricane that battered Houston, “flooding can become the major cause of death in events of this nature.”

With the storm expected to pass just north of San Juan between 6 p.m. and 8 p.m., the governor had cautioned people to take shelter by noon in homes or in one of 156 government-run facilities. He warned that the authorities would suspend rescues once winds reached 50 m.p.h.

Carmen Caballero, 69, hastily packed supplies and rushed to the nearest government shelter in San Juan around 3 p.m., after the power went out in her home and branches began to fall. As a retired doctor, she said she had offered her services to other evacuees, including two people with Alzheimer’s and some children with autism.

“This is phenomenal,” Mr. Acevedo said in a phone interview. “There is nothing like this.”

Officials warned that the island’s fragile electrical grid could be shut down for months in some areas. The Puerto Rico electric company said nearly 300,000 people had lost power by early Wednesday afternoon. More than 4,000 had lost water service, mostly because of power failures. The governor has asked the Defense Department to activate the Army National Guard for recovery efforts once the storm passes.

The hurricane could hardly have come at a worse time for the territory, which is in the throes of an economic crisis and does not have money for rebuilding.

— FRANCES ROBLES and LUIS FERRÉ-SADURNI

St. Martin’s ‘most durable’ buildings are destroyed.

The French interior minister, Gérard Collomb, said the four “most durable” buildings on St. Martin had been destroyed.

President Trump owns a property there, Le Château des Palmiers, a walled waterfront estate that is currently up for sale. It is unclear whether that property was damaged.

Power was out on St. Barthélemy, and many roofs had been blown off, according to a statement from the prefecture on the French island of Guadeloupe.

The situation on St. Martin was similar: There was no power, the fire station was flooded, and the police station no longer had a roof. The island’s administrative offices were also “partially destroyed,” the statement from Guadeloupe said, adding that the staff had taken shelter in a concrete room.

By midmorning on Wednesday, the hurricane was “pounding” the island nation of Anguilla, according to the National Hurricane Center. An officer who answered the phone at the Royal Anguilla Police Force headquarters said that one person had died in the territory.

Alex Woolfall, a British public relations consultant, was staying at The Westin St. Maarten resort in St. Martin when the storm made landfall early Wednesday. Mr. Woolfall tweeted updates during the storm before the power eventually went out.

— AURELIEN BREEDEN and KIRK SEMPLE

Evacuations in the Bahamas.

Hundreds of evacuees from the southern Bahamas began arriving in the capital, Nassau, a day after Prime Minister Hubert Minnis urged them “not to be foolish and try to brave out this monster storm.”

Marionette Simmons, 60, who left the Inagua district with three of her grandchildren, said she had stayed put during Hurricane Ike in 2008 and “wasn’t going to take that chance again.”

“My life is more important than anything I might have left behind,” Ms. Simmons said.

Dion Foulkes — the Bahamas’ labor and consumer affairs minister, who is coordinating the evacuations — said that only about 200 people had chosen to stay on the islands, which will most likely start to feel the effects of Irma on Thursday evening. Earnel Brown, who owns a small hotel in Pirates Well on the island of Mayaguana, is one of them.

“I am a person of tremendous faith, and I believe that things don’t just happen, they happen for a reason,” Mr. Brown, 54, said. “I believe everything is meticulously planned by God. I am not worried at all.”

— ERICA WELLS

Florida is taking no chances.

In Miami-Dade County, memories of the damage caused in 1992 by Hurricane Andrew, a Category 5 storm, spurred residents to prepare for Hurricane Irma earlier than usual.

Most projections have Irma slamming into the state by Sunday, although it is unclear where it might make landfall.

On Wednesday, Mr. Trump tweeted: “Watching hurricane closely. My team, which has done, and is doing, such a good job in Texas, is already in Florida. No rest for the weary!”

Gov. Rick Scott activated the state National Guard and declared a state of emergency across Florida. At a news conference, he urged residents to heed evacuation advisories and to act while the storm is still days away. Irma, he said, is more powerful and dangerous than Andrew.

“Know your evacuation zone,” he said. “Listen to your locals. This storm has the potential to devastate the state. Take it seriously.”

The governor said 1,000 National Guard troops would be on duty by Wednesday night, and ordered most state government offices closed on Friday. He urged people to stock up on basics and refill their prescriptions, and said the state was working to address shortages of fuel and bottled water.

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Purchasing plywood in Miami on Wednesday to prepare for Hurricane Irma. Most projections have the storm arriving in Florida by Sunday.CreditJoe Raedle/Getty Images

Evacuation orders for Miami-Dade County were expected Wednesday or early Thursday, Mayor Carlos Gimenez said, as a precaution for what is expected to be unprecedented coastal flooding. The county plans to open shelters on Wednesday, and ordered schools closed on Thursday.

The Florida Keys were under a mandatory evacuation order: Wednesday morning for visitors and Wednesday evening for residents. The islands’ three hospitals began evacuating patients on Tuesday.

Hurricane Harvey was weighing heavily on people’s minds. “I think because of Texas, people are freaking out,” said Yoseyn Ramos, 24, a Miami resident who said she was worried because she could not find gas anywhere.

—RICHARD PÉREZ-PEÑA and MARC SANTORA

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